Implementation of Negative Moment Reinforcement Detail Recommendations TR-723

Prestressed concrete girder bridges have historically been designed with negative moment reinforcement in order to resist loads after full continuity is achieved. The Iowa DOT Office of Bridges and Structures Bridge Design Manual calls for additional longitudinal, so called b2, bars for resistance to negative moments caused by super-imposed dead loads and live loads. In an attempt to determine if current negative moment reinforcement requirements are overly conservative, a previous study performed by Iowa State University found that the amount of so-called b2 reinforcement for negative moment regions of prestressed girder bridges may not be needed to the level currently specified (Phares et al. 2015). This finding is particularly important because current design approaches were indicating that increasing amounts of reinforcement were needed - causing both construction difficulties and increasing overall bridge costs. The goal of this project would be to evaluate the performance of a yet-to-be-constructed bridge on E57 over I35 that utilizes both current b2 amounts and the proposed reduced amounts. This would allow for the comparison of the behavior of sections with varying amounts of negative reinforcement present to help determine what requirements are necessary in the negative moment region of prestressed concrete girder bridges.

    Language

    • English

    Project

    • Status: Active
    • Funding: $149197
    • Contract Numbers:

      TR-723

      Add 606

    • Sponsor Organizations:

      Iowa Department of Transportation

      800 Lincoln Way
      Ames, IA  United States  50010
    • Managing Organizations:

      Iowa State University, Ames

      Center for Transportation Research and Education
      2711 South Loop Drive, Suite 4700
      Ames, IA  United States  50010-8664
    • Performing Organizations:

      Iowa State University, Ames

      Center for Transportation Research and Education
      2711 South Loop Drive, Suite 4700
      Ames, IA  United States  50010-8664
    • Principal Investigators:

      Phares, Brent

    • Start Date: 20170501
    • Expected Completion Date: 20210430
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01704526
    • Record Type: Research project
    • Source Agency: Iowa Department of Transportation
    • Contract Numbers: TR-723, Add 606
    • Files: RiP, STATEDOT
    • Created Date: May 9 2019 10:34AM